Who killed Kennedy? Conspiracy theories that will not die

November 15, 2013 / 12:57 PM
/ CBS News

He defected to the Soviet Union, returned to the United
States with a Russian-born wife, and tried to get Soviet and Cuban visas before
assassinating President John F. Kennedy. Fifty years later, only a quarter of
Americans are convinced that Lee Harvey Oswald acted alone. Instead, nearly 60
percent say there was a conspiracy to kill the president, according to a poll by The Associated Press-GfK in April.

Other theories cropped up almost immediately and have
endured: the Soviets murdered Kennedy or the CIA, Cuban exiles, Fidel Castro,
the country's military-industrial complex, even President Lyndon B. Johnson.
The Warren Commission found in its 879-page report on the assassination that
Oswald acted alone -- but it is still being criticized from all sides. The House
Select Committee on Assassinations concluded in 1979 that it was likely Kennedy
was killed as a result of a conspiracy.

What did happen in Dallas on Nov. 22, 1963? Who killed
Kennedy? Here are a few of those theories.

ONE BULLET OR TWO?

The Warren Commission concluded that Lee Harvey Oswald fired
three bullets, all from the Texas School Book Depository. But disagreements
persisted over whether Texas Governor John Connally was wounded by one of the
bullets that had already hit Kennedy in the neck. Skeptics pounced on the single-bullet theory
and got a boost from Connally himself who testified before the commission that
he had been hit separately. Tapes released by the National Archives in 1994
show that President Lyndon B. Johnson thought so too. And if the men were hit
at about the same time by different bullets, there had to have been a second
gunman.

A SNIPER ON THE GRASSY KNOLL?

Witnesses reported
hearing shots from the now famous grassy knoll ahead of the president's
limousine in Dealey Plaza. In a new
book, University of Virginia professor Larry Sabato reports that some Dallas
policemen who ran up the knoll encountered people with Secret Service
credentials. Who were they? The policemen let them go, and only later
discovered that there were no Secret Service agents still in Dealey Plaza, said
Sabato, the director of the Center for Politics at the University of Virginia
and author of "The Kennedy Half-Century." Conspiracy theorists,
meanwhile, poured over the amateur film made by Abraham Zapruder, frame by
frame, and insisted that it showed the president being shot from the front.

The Warren Commission said Lee Harvey Oswald fired shots from the Texas School Book Depository in Dealey Plaza in Dallas.
Dallas Police Dept. Collection/University of Texas at Austin

In 1979, the House
Select Committee on Assassinations challenged the Warren Commission's
conclusions and decided that an audio recording -- from a motorcycle policeman
whose microphone was stuck in the "on" position -- caught the sound
of four gunshots being fired, one possibly from the grassy knoll. The finding
was discounted three years later by the National Academy of Sciences which said
that the noises were made after the assassination. Sabato had the recording
re-examined and says the sounds are not gunshots at all, but an idling
motorcycle and the rattling of a microphone.

Lee Harvey Oswald, accused assassin of President John F. Kennedy, is shot by Dallas night club owner Jack Ruby.
AP

THE MAFIA

The mafia is a favorite culprit because the Mob disliked
Kennedy's brother, Robert. The
aggressive attorney general had gone after James Hoffa, the president of the
International Brotherhood of Teamsters with his own connections to the Mafia.
Plus the crime bosses were angry over Kennedy's failed attempts to overthrow
Fidel Castro, who had closed their casinos in Havana. Some accounts have crime bosses bringing over
hit men from Italy or France for the job; others accuse
the CIA of hiring mobsters to kill the president.

Then there was Jack Ruby, the Dallas nightclub owner who
shot Oswald in the basement of the Dallas police station two days after the
assassination. Ruby was connected to the Chicago mob and allegedly smuggled
guns first to Castro and then to anti-Castro groups. The Associated Press
reported the morning of the shooting that police were looking into the
possibility that Oswald had been killed to prevent him from talking.

Lee Harvey Oswald is questioned by the press at Dallas police headquarters just after midnight on Nov. 23, 1963, the day after President John F. Kennedy was assassinated.
Corbis

Oswald had Mob connections too. In New Orleans before the
assassination, he stayed at the home of an uncle who was a bookmaker with ties
to the Mafia.

The House Select Committee on Assassinations concluded that
organized crime as a group did not assassinate the president, but left open the
possibility that individual members might have been involved. It singled out
Carlos Marcello and Santo Trafficante as two men with "the motive, means
and opportunity," though it was unable to establish direct evidence of their
complicity.

FIDEL CASTRO

The Cuban dictator had no lack of motive to want the
American president dead: the failed Bay of Pigs invasion, the CIA's attempts to
kill him -- with Mob help. Only two months before the assassination, Castro
said: "United States leaders should think that if
they are aiding terrorist plans to eliminate Cuban leaders, they themselves
will not be safe."

In Philip Shenon's new book, "A Cruel and Shocking Act," Shenon reports that a Warren Commission staff member, William
Coleman, was sent to meet with Castro and was
told that the Cuban regime had nothing to do with the assassination.

A former BBC journalist and author of "Not in Your
Lifetime," Anthony Summers, writes on his blog that he first heard the
story from Coleman in 1994, though Coleman would not describe the assignment from U.S. Chief Justice Earl Warren,
saying it was confidential. Summers later recounted it and Coleman's denial in
a 2006 article in the Times of London.
Summers says Coleman brought back documents, which he said were in the
National Archives.

THE SOVIETS

The country was deep in the Cold War and Oswald had myriad
connections to the Soviet Union. After a stint in U.S. Marines, he had defected
there in 1959, and had married Marina Prusakova, whose uncle worked for Soviet
domestic intelligence. Later while in Mexico, Oswald tried to get visas for
Cuba and the Soviet Union.

Lee Harvey Oswald and his wife, Marina, are seen aboard a train as they depart Russia in 1962.
Warren Commission Report

Plus Nikita
Khrushchev's gamble to place missiles in Cuba had failed. But KGB officer
Vacheslav Nikonov told "Frontline" in 1993 that Oswald seemed
suspicious to the KGB because he was not interested in Marxism.

THE MILITARY-INTELLIGENCE COMMUNITY

Various versions have the CIA, the FBI, the Pentagon or the
Secret Service turning on Kennedy as a traitor and plotting his death. James W. Douglass in his 2008 book "JFK
and the Unspeakable: Why He Died and Why It Matters," argues that Kennedy
was killed because he had moved away from a Cold War view of the world and was
seeking peace.

Oliver Stone's movie,
"JFK," centers on New Orleans District Attorney Jim Garrison, who
conducted his own investigation of the assassination. Garrison told Playboy
magazine in 1967 that Kennedy was killed not by Oswald but by a guerrilla team
of anti-Castro adventurers and the paramilitary right. The CIA had plotted the
assassination together with the military-industrial complex because both wanted
to continue the Cold War and the escalation of the conflict in Vietnam, he
said.

The Warren Commission staff members who are still living say
that to this day no facts have emerged undercutting their conclusions: Oswald
was the assassin and neither he nor Ruby were part of a larger conspiracy. But
the conspiracy theories are likely to linger.